code: def select_field(data, key1, key2=None):
      if key2 is None:
          return [example[key1] for example in data]
      else:
          return [example[key1][key2] for example in data]
  
file_path: BLINK/elq/biencoder/data_process.py
imports: import os
  import json
  import logging
  import torch
  from tqdm import tqdm, trange
  from torch.utils.data import DataLoader, TensorDataset
  from pytorch_transformers.tokenization_bert import BertTokenizer
  from blink.biencoder.zeshel_utils import world_to_id
  from elq.common.params import ENT_START_TAG, ENT_END_TAG, ENT_TITLE_TAG
label_desc: Use image node_id 2 for calling a global function with example usage: select_field(data, key1, key2) and returns: unknown, unknown